Clinical, neuropsychological, neurophysiological, and genetic evaluations

Clinical evaluation of participants by means of Autism Diagnostic Observation Schedule, Social Responsiveness Scale, Children Behavior Check List, Conners' Scale

The MABC2 (Henderson et al., 2007) is one of the most commonly used tests for the identification of motor difficulties in children aged 3-16 years. The MABC2 includes eight subtests grouped into three areas related to different components of motor domain: manual dexterity, ball skills (such as aiming and catching), and static and dynamic balance.

The DCDQ (Wilson et al., 2007) is a parent questionnaire originally developed for estimating gross and fine motor skill difficulties in children. The questionnaire consists of 15 items investigating different subdomains of motor abilities, such as ball skills, complex motor coordination, fine and general motor skills. For each item, parents rate the children's degree of motor coordination on a 5-point scale comparing it to same-age peers.

3D kinematic data of a reach-to-drop movement are collected by a motion-capture system (The SMART D from BTS Bioengineering® - Garbagnate Milanese, Italy). The reach-to-drop task consists in reaching and grasping a ball placed over a support and dropping it in a hole (Fig. 1; Forti et al., 2011; Crippa et al., 2015). The task is simple enough to warrant compliance by all children across groups. Each participant is asked to complete at least five trials of the task with their dominant hand. Kinematic data are recorded by eight infrared-motion analysis cameras at 60 Hz with a spatial accuracy of 0.2 mm.

Magnetic Resonance (MRI) of the Brain - MRI signal allowing tridimensional multiplanar reconstruction of the brain's structures. Anatomical images obtained with high definition T1 weighted sequences of radio frequencies - the measure is a "signal (in Hz) to noise ratio" which is obtained from each voxel (tiny 3D portions of the brain)